CERN. Geneva. The LHC experiments CommitteeLHCCPHAlbanese, RAlexandrov, AAndreini, MAnokhina, ABay, ABestmann, PBetancourt, CBezshyiko, IBlanco, ABogomilov, MBondarenko, KBonivento, W MBoisseaux-Bourgeois, PBoyarsky, ABuonocore, LBuonaura, ABuontempo, SCafaro, VCallignon, MCamporesi, TCampanelli, MCanale, VCerutti, FCharitonidis, NChernyavskiy, MChoi, K-YCholak, SCicero, VConaboy, A PCongedo, LCrespo, OCristinziani, MCrupano, ADallavalle, G MDatwyler, AD'Ambrosio, NDashkina, ADe Carvalho Saraiva, JDe Bryas Dexmiers D'Archiac, P TDe Lellis, GDe Magistris, MDe Roeck, ADe Rujula, ADe Serio, MDe Simone, DDedenko, LDi Crescenzo, ADi Giulio, LDolmatov, ADurhan, OFasanella, DFedotovs, FFerrillo, MFerro-Luzzi, MFini, R AFonte, PFresa, RGalati, GGall, JGarcia Alia, RGentile, VGiordano, VGolovatiuk, AGolutvin, AGorbounov, PGorshenkov, MGraverini, EGrenard, J-LGuler, A MHaefeli, G Jvan Herwijnen, EIaselli, GIengo, PIlieva, SInfantino, AIuliano, AJacobsson, RJonker, MKamiscioglu, CKaryotakis, YKhalikov, EKim, Y GKim, S HKolev, D IKomatsu, MKonovalova, NKovalenko, SKrasilnikova, IKuleshov, SLacker, H MLantwin, OLauria, ALee, K SLee, K YLeonardo, NLerner, GLo Meo, SLoschiavo, V PLopes, LMagnan, AMaietta, MMalinin, AMaurer, YManagadze, A KMarsh, SMiano, AMikulenko, AMontanari, AMontesi, M CNaka, TNavarria, F LNinin, POgawa, SOkateva, NOsborne, JOwtscharenko, NOwen, P HOvchynnikov, MPark, B DPasseggio, GPastore, APatel, MPatrizii, LPetrov, APodgrudkov, DPetkov, G LPetridis, KPolukhina, NPrelipcean, DProta, AQueiroz, FQuercia, ARatnikov, FRedi, FReghunath, ARodrigues Cavalcante, A BRodrigues Fernandez, JRoganova, TRovelli, TRuchayskiy, ORuf, TSabate Gilarte, MSanchez Galan, FSantos Diaz, PSchneider, OSekhniaidze, GSerra, NShaposhnikov, MShchedrina, TShchutska, LesyaShevchenko, VShibuya, HShirobokov, SShmanin, ESimone, SSirri, GSoares, GSohn, J YSouaya, MStarkov, NTastet, J LTimiryasov, ITioukov, VTosi, NTrippl, CTramontano, FTsenov, RUrsov, EUstyuzhanin, AVankova-Kirilova, GVendeuvre, CVisone, CWanke, RWoo, J-KYoon, C SZamora-Saa, JZaffaroni, E2021-03-252021-03-252021-03-252021https://infoscience.epfl.ch/handle/20.500.14299/176115SND@LHC is a proposed, compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in an hitherto unexplored pseudo-rapidity region of $7.2 < \eta < 8.6$, complementary to all the other experiments at the LHC. The experiment is to be located 480 m downstream of IP1 in the unused TI18 tunnel. The first phase aims at operating the detector throughout LHC Run 3 to collect a total integrated luminosity of 150 fb$^{−1}$. Following the review of the Letter of Intent [1], submitted in August 2020, LHCC recommended the collaboration to proceed with the preparation of a Technical Proposal (TP), reported herein.Detectors and Experimental Techniquestext::report